Twenty-one of the world’s brightest young scientists gathered at Google’s headquarters in Mountain View today to celebrate their achievements and present their projects to a panel of renowned judges at the Google Science Fair finals.

Chosen from thousands of projects from more than 100 countries, these top 15 projects impressed the judges and public with their breadth of topics: from cancer research to vertical farming, 3D electronics to dementia. It was a tough decision, but we’re proud to name these three projects the winners of this year’s Google Science Fair:

13-14 age category: Jonah Kohn (USA)—“Good Vibrations: Improving the Music Experience for People with Hearing Loss Using Multi-Frequency Tactile Sound.” By creating a device that converts sound into tactile vibrations, Jonah’s project attempts to provide the hearing impaired with an improved experience of music.

15-16 age category: Iván Hervías Rodríguez, Marcos Ochoa and Sergio Pascual (Spain)—“La Vida Oculta del Agua (The Secret Life of Water).” Iván, Marcos and Sergio studied hidden microscopic life in fresh water, documenting the organisms that exist in a drop of water, and how those organisms influence our environment.

17-18 age category AND Grand Prize Winner: Brittany Wenger (USA)—“Global Neural Network Cloud Service for Breast Cancer.” Brittany’s project harnesses the power of the cloud to help doctors accurately diagnose breast cancer. Brittany built an application that compares individual test results to an extensive dataset stored in the cloud, allowing doctors to assess tumors using a minimally-invasive procedure.

Each of the winners will receive prizes from Google and our Science Fair partners: CERN, LEGO, National Geographic and Scientific American. This evening, we also recognized Sakhiwe Shongwe and Bonkhe Mahlalela, from Swaziland, the winners of the Scientific American Science in Action award.

The judges were impressed with the quality of all the projects this year—and by the ingenuity, dedication and passion of the young scientists who created them. We applaud every contestant who submitted a project to the 2012 Google Science Fair and look forward to seeing the innovations, inventions and discoveries of young scientists in the years to come.